Calculating machine



Patented Nov. 14, 1944 UNITED STATES PATENT OFFICE 1 Claim.

My invention relates to calculating machines and has particular reference to machines for making addition and multiplication.

My invention has for' its object to provide a machine which can be used to add numbers and which can be also used for rapid and simple operations of multiplication, by employing special selected numbers which, when added together, will give the required answer. My machine for this purpose consists of an attachment for an ordinary adding machine to which is added a secondary keyboard so arranged that depression of one of the secondary keys registers a complete number, preferably having two digits. For convenience I prefer to use a mechanism in which the final result only is printed on a strip of paper, omitting intermediate numbers used for obtaining the result.

The secondary keys bear key numbers, every key number being connected to register a certain definite answer number on the adding mechanism of the machine. For finding the key numhers, I provide two indicators, one of which is stationary and serves to indicate one of the factor numbers to be multiplied, the other indicator bein slidably mounted and adapted to indicate the second factor number whose digits are reversed, i. e., the last digits are placed first. The key numbers. are found by the juxtaposition of the factors.

My invention is more fully described in the accompanying specification and drawing in which:

Fig. 1 is a top plan view of my machine in one embodiment of my invention;

Fig. 2 is a side view of the same;

Fig. 3 is a detail view of a magnet for operating primary keys;

Fig. 4 is a supplementary key which may be used for operating the primary keys;

Fig. 5 is a detail view of a frame advancing mechanism.

My machine is especially adapted to be used in connection with my method of making multiplications, the method being based on the use oi certain "key" and "answer numbers as follows:

Answer numbers For using my method an ordinary adding machine may be used with a special attachment.

Such an attachment to an ordinary machine such as Burroughs, Victor, etc, is shown in Figs. 1 to 5 inclusive (the operating crank is omitted on the drawing). The attachment consists of a frame I slidably fitted over an ordinary adding machine 2, the latter having a keyboard with primary keys 3, numbered from 1 to in consecutive rows. The answer or the sum of added numbers may be indicated on a rotary index mechanism 4 or may be printed on a strip of paper by any suitable mechanism employed for this in adding machines such as Burroughs,

etc.

A stationary indicating member 6 is mounted on the machine, the member comprising a plurality of wheels I, every wheel having printed numbers from 1 to 0. The wheels are provided with numbers to indicate units, tens, hundreds, etc. Any desired number can be indicated on the member 8 by turning the wheels I, a handle 8 being provided for resetting the device.

The sliding frame I has a similar: indicator 8 with wheels In and a resetting 'thumbhead or handle II. The indicator can be made for any desired number of digits.

The frame I with the indicator 8 can be moved to the left from its initial position in which the last wheel I0 registers with the first wheel I, by a spring pawl I2 shown in detail in Fig. 5, pivoted to the frame I at I3 and engaging a rack I4 attached to the machine 2. A shift key I5 extends through the frame I and is held raised by a spring I6. By depressing the key IS, the frame is moved one notch over the rack, thereby stepping up one decimal space on the machine. Rollers I! (Fig. 2), can be provided if desired to facilitate the movement of the frame. The frame is guided at the front by the edge of the machine and at the rear by a suitable rail on the machine (not shown). The frame is restored to the original position by moving it by hand.

The left portion of the frame has an opening I8, exposing the primary keys 3 of the adding machine, the frame I can be made to fit a suitable ordinary adding machine or, preferably, a so-called calculator, such as Burroughs Calculator," American Arithmameter," Allen- Wales, etc. With machines employing a crank for registering the member, a suitable extension may be added to the crank to clear the frame of my attachment. The right side of the frame covers two rows of the primary keys and is provided with key-operating plungers 28, registering with the corresponding primary keys. The plungers are held in a raised position by springs 2| (Fig. 3) and have caps 22 which can be manually operated for depressing the corresponding primary keys.

The plungers can be also electrically operated, being provided with solenoids or magnet coils I9 connected by a common lead 23 with a source of electric current 24, and by leads 25 with switches 26 (Fig. 2) operated by secondary keys 24 of a secondary keyboard 23, the switches being connected with the source of current 24 by leads 21. The secondary keyboard forms a unit with the frame I and moves together with the latter.

Mechanical plunger 22 (Fig. 4) may be employed over the primary keys 3 if the frame has a solid upper deck without the opening I8, as shown fractionally in Fig. 4, frame I.

The connections are so made that every secondary key operates simultaneously two primary keys. Every secondary key is marked with a key number comprising two ciphers or digits as shown in Fig. 1, there being keys.

Two circuits are shown in Fig. 1 for the key 7 numbers 21 and 28, which are connected for operating primary keys I0, 4 and III, 8 respectively. The magnet coils 21 are divided into sections as shown in Fig. 3 for different circuits in order to avoid interfering stray currents between different circuits.

For adding, the combined machine is used in an ordinary manner. For multiplication, the machine is used as follows:

The first of the factors or numbers to be multiplied is set up on the indicator 5. The second factor is similarly set up on the movable indicator 9 but in reversed order of its digits, 1. e., making the last digit the. first. The frame is placed in the extreme right position as shown In Fig. 1. The registering digits on the two indicators represent then the first key number, care being taken to read always from the low to the high number. Thus is read 09, 41 as 14, etc. If the key number has two significant digits, it is located on the secondary keyboard and the corresponding key depressed, causing operation of two result keys on the machine. Thus, if the key number is 21, the corresponding key is depressed, energizing coils of the electric keys I and 4 as shown in Fig. 1. Upon actuation of the crank, if the adding machine is crank operated. the result number will be then registered on the indicator 4, or, if desired, may be printed on the strip of paper 5.

The shift key I! is then depressed, moving the frame with the indicator 8 one step to the left. There will be two registering sets of numbers so that two secondary keys must be depressed, and the operating crank must be operated once for each depression of a secondary key the result being added in the next decimal column of the registering indicator 4.

The operation will be continued until the last registering numbers are converted into results and registered on the indicator 4, showing the final result of the multiplication.

The number of secondary keys is 45 as shown, but it can be reduced to 36 as shown in Fig. 8 in view of the fact that certain results correspond to two different key numbers. Thus 19 and 33 correspond to the same result number 09 so that a single secondary key can be employed for this result.

Example I It is desired to multiply 785 by 348. The numbers are registered on the indicators 8 and 9 as follows:

the second factor being reversed. The registering digits (reading with the smaller digit first) 58 are found on a secondary key, which is depressed, registering result number 40 on the indicator 4. The frame is then moved one step to the left so that two digits register together;

We have two key numbers; 88 and 45. The corresponding secondary keys are depressed, registering and adding the result numbers 64 and 20 on the indicator 4. The latter therefore will indicate the sum of the result figures:

The frame is again moved one step so that three numbers will be registered:

The key numbers will be '78, 48 and 35. The corresponding result numbers will be added to the previous result:

The next movement of the frame will bring two numbers together:

The next and final movement will bring two numbers together:

The key number will be 37 and the result number 21 to be added to the previous result:

The complete answer is obtained by punching 9 secondary keys and shii'ting the frame 4 times. With an ordinary calculating machine it would be necessary to punch 3 keys to make 3 shifts and to make 15 revolutions of the crank. With a simple adding machine the same result could be obtained by punching the keys 45 times and operating the crank if the machine requires crank operations for registering the numbers.

The frame I in Fig. 1 can be also made to move from left to the right, adding first, the highest digit and following by mixed lower digits. Such an arrangement has an advantage in that the multiplication can be stopped at any desired place, with any desired degree of accuracy, if, for instance, fractional numbers are being multiplied. In the machine shown in Figs.

'7 and 8, the sliding indicator 9 can be made to move' from the left to the right.

It is understood that my calculating machines andmethods may be further modified without departing from the spirit of the invention, as set forth in the appended claim.

I claim as my invention:

An attachment for an adding machine for multiplying numerical factors comprising a frame adjustable over an adding machine keyboard; two banks of manually operable plungers movably supported on the frame and operable to depress the keys of two adjoining banks of the adding machine; a plurality of magnet coils mounted on the frame at every plunger; a secondary keyboard, and a switch at every key of the secondary keyboard connected in a circuit with the coils of one or two plungers belonging to the two banks of plungers; and means to shift the frame step by step to position the'plungers over successive pairs of banks of the adding machine keyboard.

SAMUEL I. KRIEGER. 

